Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Triangulum Pinwheel: 02-01 (87), 02-02 (87), 02-03 (86), 01-31 (85), 02-04 (83) — by astronomy; check the weather when the night is within four days.

2029-01-27astronomy score per night — click a bar for that night2029-02-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-01-27 Sat	30	—	unknown	19:10–23:00 (marginal, 3.83 h)	79.1° 17:30	10.91	93%	66.2°
2029-01-28 Sun	40	—	unknown	19:10–20:15 (good, 1.08 h)	79.1° 17:25	10.88	98%	79.6°
2029-01-29 Mon	52	—	unknown	19:10–21:35 (good, 2.42 h)	79.1° 17:20	10.84	100%	93.4°
2029-01-30 Tue	66	—	unknown	19:10–22:25 (good, 3.25 h)	79.1° 17:15	10.81	99%	107.4°
2029-01-31 Wed	85	—	unknown	19:15–22:35 (good, 3.33 h)	79.1° 17:10	10.78	96%	121.6°
2029-02-01 Thu	87	—	unknown	19:15–22:30 (good, 3.25 h)	79.1° 17:10	10.75	90%	135.5°
2029-02-02 Fri	87	—	unknown	19:15–22:30 (good, 3.25 h)	79.1° 17:05	10.71	82%	148.9°
2029-02-03 Sat	86	—	unknown	19:15–22:30 (good, 3.25 h)	79.1° 17:00	10.68	72%	160.4°
2029-02-04 Sun	83	—	unknown	19:20–22:30 (good, 3.17 h)	79.1° 16:55	10.65	61%	165.5°
2029-02-05 Mon	81	—	unknown	19:20–22:25 (good, 3.08 h)	79.1° 16:50	10.61	50%	159.3°
2029-02-06 Tue	78	—	unknown	19:20–22:20 (good, 3.0 h)	79.1° 16:50	10.58	39%	148.1°
2029-02-07 Wed	76	—	unknown	19:20–22:15 (good, 2.92 h)	79.1° 16:45	10.54	28%	135.9°
2029-02-08 Thu	74	—	unknown	19:20–22:15 (good, 2.92 h)	79.1° 16:40	10.5	19%	123.4°
2029-02-09 Fri	71	—	unknown	19:25–22:10 (good, 2.75 h)	79.1° 16:35	10.47	12%	110.9°
2029-02-10 Sat	69	—	unknown	19:25–22:05 (good, 2.67 h)	79.1° 16:35	10.43	6%	98.5°
2029-02-11 Sun	66	—	unknown	19:25–22:00 (good, 2.58 h)	79.1° 16:30	10.39	2%	86.3°
2029-02-12 Mon	64	—	unknown	19:25–21:55 (good, 2.5 h)	79.1° 16:25	10.35	0%	74.3°
2029-02-13 Tue	61	—	unknown	19:30–21:55 (good, 2.42 h)	79.1° 16:20	10.31	0%	62.5°
2029-02-14 Wed	59	—	unknown	19:30–21:50 (good, 2.33 h)	79.1° 16:15	10.27	2%	50.9°
2029-02-15 Thu	55	—	unknown	19:30–21:45 (good, 2.25 h)	79.1° 16:15	10.23	6%	39.7°
2029-02-16 Fri	50	—	unknown	19:30–21:40 (good, 2.17 h)	79.1° 16:10	10.19	11%	29.1°
2029-02-17 Sat	42	—	unknown	19:35–21:30 (good, 1.92 h)	79.1° 16:05	10.15	18%	19.9°
2029-02-18 Sun	35	—	unknown	19:35–21:20 (good, 1.75 h)	79.1° 16:00	10.11	25%	14.7°
2029-02-19 Mon	29	—	unknown	19:35–21:10 (good, 1.58 h)	79.1° 15:55	10.07	34%	17.6°
2029-02-20 Tue	22	—	unknown	19:35–19:55 (good, 0.33 h)	79.1° 15:55	10.03	43%	26.2°
2029-02-21 Wed	17	—	unknown	19:35–21:40 (marginal, 2.08 h)	79.1° 15:50	9.99	53%	36.9°
2029-02-22 Thu	15	—	unknown	19:40–21:35 (marginal, 1.92 h)	79.1° 15:45	9.94	63%	48.5°
2029-02-23 Fri	14	—	unknown	19:40–21:30 (marginal, 1.83 h)	79.1° 15:40	9.9	73%	60.9°
2029-02-24 Sat	15	—	unknown	19:40–21:25 (marginal, 1.75 h)	79.1° 15:40	9.86	82%	73.8°
2029-02-25 Sun	17	—	unknown	19:40–21:25 (marginal, 1.75 h)	79.1° 15:35	9.81	89%	87.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-01-27&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.